GHSA-JJ7H-C3HG-M23X Authlib: is_secure_transport() loopback exemption can be bypassed with a userinfo component, allowing cleartext-HTTP URLs to non-loopback hosts

Summary authlib.common.security.issecuretransport is used throughout Authlib to enforce the OAuth 2.0 / OIDC requirement that endpoint and redirect URIs use TLS, with an RFC 8252 §7.3 exemption for loopback http:// URIs. The check is implemented as a textual str.startswith prefix match, so a URL...